Agile development books often skip bug management practice. However, there are several dangerous misunderstandings (anti-patterns) that are quite common. It is better to recognize the problem early and fight to win. Here are three common bug management anti-patterns in a development process.

Bug fixing phase inside iteration

Symptom: You have several days at the end of iteration fully dedicated to bug fixing.

If you have a bug fixing phase inside an iteration, you have mini-waterfall in each iteration, which is not a very good idea (in agile we blame waterfall for good reason, don’t we?). Story should be tested as soon as it is completed.

Bug fixing iteration

Symptom: You run several iterations with almost no or little bug fixing and then one (or even two!) iterations fully dedicated to bug fixing.

Bug fixing iterations kill your iterative development. It is even worse than mini-waterfall. Such iterations increase your work in progress dramatically. You have nothing done during several iterations before bug fixing iteration. You have nothing to ship. Moreover, bug fixing iterations reduce motivation, people don't like to fix bugs for 2 weeks or for the whole month.

No “Zero open bugs” rule in user story’s Definition of Done

Symptom: You have open bugs in a completed iteration.

You may have decided that some bugs discovered during story development are unimportant and can be postponed to future releases/iterations. This is a very dangerous practice that leads to bugs accumulation. Moreover, it may be a reason for Bug fixing iteration (see above). The best strategy is to have “Zero open bugs” rule in Definition of Done for user story.